1. Field of the Invention
The present invention relates to mixers. More particularly, the present invention relates to mixers for mixing high-viscosity fluids. Furthermore, the present invention relates to mixing apparatus that utilize a hydraulic motor for driving a mixer shaft.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Current mixers that are used to mix fluids in drums are not adequate for viscous materials. In many circumstances, it is important to mix the materials thoroughly before application. This is because some materials will separate within the drum after being originally mixed by the manufacturer. When the materials separate, the product that is dispensed from the drum may have inadequate properties, may not work effectively, and may cause quality control problems.
The preparation a polymeric foams conventionally required the mixing of several components which react to form a foamed polymer. Typically, the components include a polyol, an isocyanate, a catalyst or catalysts, a surfactant and water. When these components are mixed together in the correct proportions, the water reacts with the isocyanate to produce carbon dioxide for expansion of the polymer.
In the past, the inadequate mixing of the polymeric material within the drum can cause various problems. On a typical process, an operator is assigned to monitor the foam surface. If inadequate mixing of the polymer occurs, it was necessary for the operator to increase the mixer speed. If the foam surface is still inadequate after the increase of mixer speed, other adjustments are required, including reduction of throughput of blowing agent and polymer. These changes, however, can reduce the output of the given equipment. Also, in the past, there is never been an early warning signal that mixing conditions were inadequate. The control of the uniformity of the product properties has largely been an art rather than a science because the change of level of one variable in the process typically changes more than one of the product properties. In particular, these problems associated with the foam surface can occur because the polymer in the drum is adequately mixed.
In certain circumstances, drums of the polymeric foam and other high-viscosity materials will be unused for a long period of time. When these materials are finally used, the components have separated to a certain extent within the drum. When the foam has become separated, it is necessary for the operator to thoroughly mix the components in the drum. However, these mixing operations are very inconvenient and difficult. In certain circumstances, the operator will simply disregard the need to effectively mix the components within the drum. In other circumstances, large air-powered mixers or electric motor mixers must be employed in order to address the problem of the inadequate mixing and separation within the drum. These items are quite expensive, heavy, and difficult to use. As such, a need has developed so as to provide a mixer apparatus and system whereby high-viscosity fluids in a drum can be easily mixed.
There are two types of mixers that are currently utilized. These include an air-powered motor mixer and an electric motor mixer. Both types of these mixers have problems associated therewith.
The air-powered motor mixer uses compressed air from a source in order to twist the air-powered motor mixer. The air-powered mixer is a variable-speed mixer, but it has constraints. When used in the foam industry, all of the spray equipment utilizes some type of air compressor within their mobile equipment. However, most air compressors are sized to be just large enough to run the spray gun and the transfer pumps. They are not large enough for the air-powered motor mixer. The greater amount of cubic feet per minute that is available for the air-powered motor mixer, the faster and more powerful the mixer becomes. However, this is not normally the case in typical spray equipment.
Electric motor mixers are very large and bulky. The mixer uses electricity for power to directly couple the motor shaft with the mixer blade. They mount in the same manner as the air-powered motor mixer, but are much larger. Consequently, the electric motor mixer begins to vibrate and move around when turned on to mix. Also, most electric motor mixers have a high RPM (1750 RPMs). It can possibly break the lid of the drum that it is mounted to if the electric motor is left on for too long of a period of time. Electric motor mixers can weight close to fifty pounds. As such, the sheer weight of the electric motor mixer discourages its use by most operators.
In the past, various patents have issued relating to mixing apparatus. For example, U.S. Pat. No. 3,089,683, issued on May 14, 1963 to Thomas et al., teaches a mixer for viscous fluids. This variable-speed mixer compensates for variations in the viscosity of the material being mixed. An electric motor drives a differential with two outputs. One output is connected to a mixer shaft and another to a variable impedance. The variable impedance varies the speed of the mixer shaft in response to the load on the shaft, thereby maintaining the torque applied to the shaft at a constant level and controlling the differential to provide a constant load on the electric motor.
U.S. Pat. No. 3,941,357, issued on Mar. 2, 1976 to W. O. Wirtz, describes a method and apparatus for mixing viscous materials. The apparatus is a double-arm mixer having a container with a pair of spaced-apart shafts pivotally disposed through the container and a plurality of mixing plows connected to the periphery of each shaft in spaced-apart relationship. When the shafts are rotated in opposite directions, the working tools force the viscous material to the bottom of the container so that at its densest point, it interacts between the shafts before it is divided.
U.S. Pat. No. 4,120,051, issued on Oct. 10, 1978 to F. M. Lohning, teaches a mixing apparatus for mixing fluids, such as drilling fluids, in a reservoir. Each fluid has different densities requiring different torques for proper mixing. The mixing apparatus controls the motor mechanism for limiting the maximum horsepower of the motor mechanism that is absorbed in the mixing of the fluid to substantially the rated horsepower of the motor mechanism so as to prevent overloading of the motor mechanism.
U.S. Pat. No. 4,506,982, issued on Mar. 26, 1985 to Smithers et al., provides an apparatus for continuously blending viscous liquids with particulate solids. This apparatus includes a vertical cylindrical tank in which is disposed a smaller vertical vessel defining a blending chamber. Open lower side regions of the vessel feed the blended slurry to a holding chamber defined between the vessel and the tank. A shaft is rotatably mounted through the blending chamber and has a blending disk affixed thereto and two hollow blending cones coaxially mounted on opposite sides of the disc to form two shear-type blending regions. Hydraulically-driven pumps and motors feed the viscous liquid and solids to the blending chamber, rotate the blender shaft, and withdraw slurry from the holding region for use.
U.S. Pat. No. 5,094,541, issued on Mar. 10, 1992 to R. D. Nelson, provides a mixing apparatus for mixing materials of various consistencies. This mixing apparatus includes a pair of mixer shafts having radially-extending blades thereon for mixing the material as the shafts rotate. Each shaft is driven by a hydraulic motor and the hydraulic motors are located in separate hydraulic fluid circuits. The relative rotational orientation of the shafts to each other is controlled by appropriate control of the separate hydraulic fluid circuits.
U.S. Pat. No. 6,910,799, issued on Jun. 28, 2005 to C. K. Renfro, teaches a mixing apparatus that has a blade mixer affixed to the end of a mixer shaft. The mixer shaft is slidably mounted through a mixer seal member which is adapted to be brought into sealing engagement with the open filler end of a retail tube of viscous caulking compound. The shaft and the mixer are adapted to be reciprocated through the viscous compound contained in the tube substantially for the entire length of the tube so as to rapidly and intimately mix the compound with a colorant injected thereinto.
International Publication No WO 95/11120, published on Apr. 27, 1995 to I. Dall, describes a mixer that serves to mix a viscous material such as concrete. The mixer includes a stirring unit and a mixing vessel having a closable discharge opening. The mixer also includes a scraper mechanism that is caused to describe an orbital movement about a central axis in the vessel by the stirring unit. The scraper mechanism serves to raise a scraper blade above the material during mixing and down into a drain discharge.
Canadian Patent No. 2 077 926, published on Sep. 10, 1992 to H. Cholet, describes a continuous mixing apparatus having a rotating shaft equipped with blades. The mixture obtained at the mixer output results from the admission to the mixer of a high-viscosity fluid and at least a lower-viscosity fluid. A hydraulic pump is connected to the body via an outlet thereof. A first conduit brings crude oil to the inlet of the mixing device. A second conduit connects the output of the mixing device to the inlet of the pump. A hydraulic motor rotates the rotary shaft of the mixing device. An engine fluid injection duct connects an injection plant to the surface and to the engine.
European Patent No. 1787 712, published on May 23, 2007 to M. Buck, discloses a device for mixing a first fluid and a viscous or powdered component. These liquid and the viscous components are supplied into a mixing chamber of a mixing body. The mixing product is cyclically transportable by means of a conveyance element.
International Publication No. WO 01/43858, published on Jun. 21, 2001 to Z. Herbak, provides a device for mixing viscous liquids. This device comprises a cylindrical mixing chamber which is open at a face side and has a sidewall. At least two injection nozzles have nozzle openings at exit bores in the sidewall. A piston can be displaced in the mixing chamber in a longitudinal axial direction along the longitudinal axis of the mixing chamber. The mixing chamber can be displaced along a longitudinal axis and can also be rotated using a motor.
It is an object of the present invention to provide a mixing apparatus that can mix high-viscosity fluids of greater than 2000 cps.
It is another object of the present invention provide a mixing apparatus that can be used with standard drums and totes.
It is another object of the present invention to provide a mixing apparatus that can be insertable through a bunghole of a drum.
It is another object of the present invention to provide a mixing apparatus that uses a small-sized hydraulic motor.
It is another object of the present invention to provide a mixing apparatus which is portable and easily installed.
It is another object of the present invention to provide a mixing apparatus that can drive two mixers from the same hydraulic pump.
It is a further object of the present invention provide a mixer apparatus that avoids the use of undersized air compressors and electric motors.
It is a further object of the present invention provide a mixer apparatus that is lightweight and compact.
It is still a further object of the present invention provide a mixer apparatus that is particularly effective in mixing polymeric foam material in drums.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.